FIONREAD(2const) FIONREAD(2const)
NAME
FIONREAD, TIOCINQ, TIOCOUTQ, TCFLSH, TIOCSERGETLSR - buffer count and
flushing
LIBRARY
Standard C library (libc, -lc)
SYNOPSIS
#include <asm/termbits.h> /* Definition of constants */
#include <sys/ioctl.h>
int ioctl(int fd, FIONREAD, int *argp);
int ioctl(int fd, TIOCINQ, int *argp);
int ioctl(int fd, TIOCOUTQ, int *argp);
int ioctl(int fd, TCFLSH, int arg);
int ioctl(int fd, FIONREAD, int *argp);
DESCRIPTION
FIONREAD
Get the number of bytes in the input buffer.
TIOCINQ
Same as FIONREAD.
TIOCOUTQ
Get the number of bytes in the output buffer.
TCFLSH Equivalent to tcflush(fd, arg).
See tcflush(3) for the argument values TCIFLUSH, TCOFLUSH,
TCIOFLUSH.
TIOCSERGETLSR
Get line status register. Status register has TIOCSER_TEMT bit
set when output buffer is empty and also hardware transmitter is
physically empty.
Does not have to be supported by all serial tty drivers.
tcdrain(3) does not wait and returns immediately when TI-
OCSER_TEMT bit is set.
RETURN VALUE
On success, 0 is returned. On error, -1 is returned, and errno is set
to indicate the error.
SEE ALSO
ioctl(2), ioctl_tty(2), tcflush(3), termios(3)
Linux man-pages 6.9.1 2024-06-13 FIONREAD(2const)
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